After installing mongodb with brew in OS X environment
Import a json file according to the tutorial on official documents
Input:

mongoimport --db test --collection restaurants --drop --file primer-dataset.json

An error was reported during the process.

Failed: error connnecting to db server: no reachable servers

Seek a solution

Solutions already tried:
1.mongoimport --host=127.0.0.1 --port=27017 --db test --collection restaurants --drop --file primer-dataset.json
2.brew update && brew upgrade

Add:
1. Import the file after starting mongodb and report an error:

Failed: error processing document #9870: unexpected EOF